1. Field of the Invention
The invention generally relates to marking instruments and materials for producing marking instruments. More particularly, the invention relates to marking instrument materials that encase a marking mass.
2. Brief Description of Related Technology
Marking instruments, including cosmetic marking instruments, employ a variety of materials to hold the marking material or cosmetic mass. The container for the marking can both protect the user's hands from marking, and protect the marking material from the environment. Thus, for example, a crayon generally includes a paper wrapping, a pencil generally includes a wooden barrel, and a lipstick generally includes a synthetic resin plastic applicator or container.
In many applications, the color or shade of a marking material can be discerned only from an exposed portion (e.g., tip end) of the marking material, or is indicated by decorating the container for the material with the same (but, often, only similar) color. Thus, there is a general need for transparent or translucent containers, such that the shade of a marking material can be discerned by mere inspection of the article as a whole. In addition, conditions such as chemical compatibility between a housing material and a marking material, structural and dimensional suitability of housing materials, and forming ability of housing materials must be satisfied for particular applications. In particular, for pencils, the ability to sharpen a pencil (including the selective removal of barrel material by cutting) can be important in certain applications.